AT LEAST 50 people were slaughtered in a gay nightclub in Orlando, Florida, yesterday morning at the hands of a man with an automatic rifle.

Local authorities said that they were investigating the massacre as an act of terrorism.

The gunman, named by authorities as Omar Mateen, was killed later in a shoot-out with armed officers who had exploded a small device to distract him.

“This is an incident, as I see it, that we certainly classify as a domestic terror incident,” said Orange County Sheriff Jerry Demings.

At least 53 other people were taken to hospital, most in a critical condition, and a surgeon at Orlando Regional Medical Centre said that the death toll was likely to climb.

Although Mateen had another handgun and carried a device of some kind, Orlando Mayor Buddy Dyer said that all of the dead had been killed with the assault rifle.

“There’s blood everywhere,” he said of the horrific scene in the club known as Pulse.

The gunman had exchanged gunfire with an officer working at the club at around 2am just as it was closing and more than 300 people remained in it.

He then went back inside and took hostages, said police chief John Mina said.

Authorities despatched a special weapons and tactics team three hours later to rescue the hostages.

Eyewitness Jackie Smith, who was in the club and saw two friends shot, said: “Some guy walked in and started shooting everybody. He had an automatic rifle, so nobody stood a chance.

“I just tried to get out of there,” she added. When asked if the gunman had any connection to radical jihadist terrorism, FBI agent Ron Hopper said that the authorities had “suggestions that individual has leanings towards that.”

Police said that they had secured the suspect’s vehicle, a van, right outside the club.

“We condemn this monstrous attack and offer our heartfelt condolences to the families and loved ones of all those killed or injured,” said Rasha Mubarak, Orlando regional co-ordinator for Florida’s chapter of the Council on American-Islamic Relations.

“The Muslim community joins our fellow Americans in repudiating anyone or any group that would claim to justify or excuse such an appalling act of violence.”

An Equality Florida spokesperson said: “We are heartbroken and angry that senseless violence has once again destroyed lives in our state and in our country.

“Gay clubs hold a significant place in LGBTQ history. They were often the only safe gathering place and this horrific act strikes directly at our sense of safety.”

Human rights campaigner Peter Tatchell said: “There was always a possibility that Islamist extremists would target gay communities in the West, whether as lone attackers or via organised terrorist cells. They have a pathological hatred of LGBT people, and also of Jews and liberal Muslims.

“The condolences expressed by Florida Senator Marco Rubio are sickening hypocrisy. He has repeatedly opposed gay equality, including wanting to repeal same-sex marriage and protection against discrimination for LGBT employees. His anti-gay sentiments have fanned the flames of homophobic hatred.”

And Santa Monica police arrested a man found with assault rifles and possible explosives in his car shortly before the Los Angeles Pride festival, the LA Times reported late yesterday.

The man reportedly mentioned the Pride event and told police he was waiting for a friend before his vehicle was searched and several weapons found. There was no known link to the Orlando shooting as the Star went to press.

The murderous rampage comes after singer Christina Grimmie, a former contestant on The Voice, was shot and killed by “obsessed fan” Kevin James Loibl on Friday night while signing autographs after her show in Orlando, Florida.